Why did Sudan have a long civil war?

This is a long-term struggle: since the British suddenly handed over the control of the country to the Muslim and Arab-dominated North, the Christian or animist-dominated South has been fighting for independence, and the conflict between the two sides has killed nearly two million people. It is widely predicted in the west that the referendum held in southern Sudan will lead to the split between the north and the south of the country. As China has a large amount of oil business in all parts of Sudan, it will inevitably face some risks. Some recent comments in western media are like waiting to see China's jokes. However, the risk of China's oil business comes more from the stability of southern Sudan than from the emergence of a regime hostile to China once Sudan is divided. China has always insisted on non-interference in Africa's internal affairs, which has been criticized by the West many times, but it is precisely by insisting on doing so that the risk of China before the political changes in Africa is minimized. China has never met a hostile country in Africa, and the friendship between Sudan and China is no exception. China has entered all African countries on an equal footing, not only doing business there, but also helping to build bridges, pavements, hospitals and schools. We are confident that if Sudan continues to be reunified, it will be friendly to China, and if it is divided into two parts, the northern and southern regimes will be friendly to China. In the past few years, many friendly countries of China have experienced political turmoil, such as Balkan countries such as Serbia, Middle Eastern countries such as Iraq, and Central Asian countries such as Kyrgyzstan. The new regimes of these countries have continued their friendly policies towards China, and the political tide has not reduced the number of friends in China. China advocates a win-win situation in its contacts with all countries, and never seeks a single win for China. Countless win-win situations add up to China's "big win". The west always thinks that the change of ideology will make some small countries deviate from China, and China's investment in some countries will make China involved in local politics, because they don't understand what a win-win situation advocated by China is. The single win they pursue is to exert their strength and often lose both, but a win-win situation is twice the result with half the effort. China's national strength is much worse than that of the United States, even worse than that of European powers in many aspects, but the real reason why China is developing well in Africa is as simple as that. China doesn't want to force the Sudanese to change anything. China only wants the Sudanese referendum to go smoothly. No matter what the outcome is, both the North and the South can accept it peacefully and calmly. China's attitude is sincere, because it is sincere, it is effortless and good for both people and themselves. We think the west is quite nervous, because they are only willing to accept one result and not another, so they will always work hard. At this turbulent moment, it is suggested that PetroChina and other enterprises in Jiangsu and China should take good care of their employees, protect their property as much as possible, and make them full of confidence in the long-term future of local business. Short-term uncertainty is the cost of all enterprises, and neither South Sudan nor North Sudan is a special place.